A steam generator of a steaming system is typically filled with tap water which normally contains various gases as well as salts. Salts which are customarily found in tap water include sodium bicarbonate, sodium sulfate and magnesium bicarbonate. The percentage of sodium and magnesium salts determines the hardness of water. The heating entails decomposition of water into its constituents, and such constituents, especially carbonates, deposit on the adjacent surfaces in the form of scale. The scale is an insulator of heat so that the energy requirements of the steam generator increase as the thickness of the scale increases. The scale can be carried over with the steam to the outlet of the steam generator, causing the clogging of steam vents and staining users' articles. The steam rate can also be reduced due to the clogging of the steam vents. The common practice is to rinse the steam generator on a regular basis, for example, for every 1 to 2 months, to bring down the scale level and thus to prevent the carry-over.
Another way of improving the situation is to improve the quality of inlet water by pre-treating. The pre-treatment is carried out by using an ion exchange or other anti-scaling agents to remove the calcium and magnesium ions in the inlet water. The treatment agents have to be replaced or re-generated after a certain amount of water treatment.
FR 2632331 discloses a household electrical steam appliance comprising a water reservoir which has a filling orifice. This reservoir communicates with a vaporization chamber. It additionally comprises means for introducing a predetermined quantity of a chemical compound into the water reservoir. This application is especially for preventing the formation of scale in a household electrical steam appliance such as a smoothing iron. However, it is necessary to periodically examine if the corresponding cartridge contains the chemical compound or it must be replaced. In addition, the mechanical dosing device is complex and thus costly.
Therefore, it is an object of the invention to provide a steaming system which does not have the disadvantages of the known steaming system described before, in particular to provide such a steaming system which endows a user with ease of generating quality steam.
This object is achieved by features of the independent claim. Further developments and preferred embodiments of the invention are outlined in the dependent claims.